Bulkable nylon yarn



United States Patent 3,421,935 BULKABLE NYLON YARN Neil L. Finch, Kinston, N.C., assignor to E. I. du Pont de Nemours and Company, Wilmington, Del., a corporation of-Delaware No Drawing. Filed Aug. 12, 1965, Ser. No. 479,280

US. Cl. 117-138.8 4 Claims Int. Cl. D01f .7/ 06'; D06rn ABSTRACT OF THE DISCLOSURE Continuous filament, bulkable nylon yarn having on its surface a lubricating composition comprised of specific proportions of coconut oil, the tetraoleate-laur-ate pentaester of the condensate of one mol of sorbitol with about 30 mols of ethylene oxide, and the polyether condensate of nonylphenol and about 6 mols of ethylene oxide.

This invention relates to textile lubricants for polyamide yarns which are to be bulked in a high-temperature process.

As is known, yarns prepared from synthetic polymers can be bulked by crimping the yarns in a zig-Zag pattern in a heated stuffing chamber. During passage through the chamber the crimp is set and the yarn is thus stabilized in a bulked form. While passing throughthe heated chamber, the yarn must be lubricated in a manner that permits uniform movement and treatment of the yarn. The lubricant employed must not give rise to deleterious effects under the conditions of operation, for example when subjected to the heat used in crimping.

Accordingly, it is the primary object of this invention to provide a composition for the lubrication of yarns at elevated temperatures without adversely aliecting yarn performance or properties.

This and other objects are attained in the present invention in a continuous-filament nylon yarn which contains a lubricating composition consisting essentially, by Weight, of about 55 to 60 parts coconut oil, about 25 to 30 parts of the tetraoleat-e-laurate pentaester of a mole of sorbitol condensed with about 30 moles of ethylene oxide and about 15 parts of the polyether obtained by condensing a mole of nonylphenol with about 6 moles of ethylene oxide.

The lubricating composition of the invention consists of an intimate blend of a lubricant and two different types of ethylene oxide condensates, each of which individually is well-known and commercially available. Some variation in'fthe relative amounts of the constituents and in the components of the condensates is permissible, but such variation should be kept to a minimum. For example, the preferred amount of coconut oil is about 58 percent by weight. If the amount of coconut oil is increased appreciably above 60 percent, the viscosity of the over-all composition will change and optimum lubrication cannot be expected. In addition, such an increase will necessarily be at the expense of the emulsifier. This would be undesirable because the composition is applied as an aqueous emulsion, and lowering the emulsifier content can only lead to a commensurate loss in emulsion stability. In like manner, alterations in the nature of the condensates or in their relative ratio can be expected to cause a decline in performance.

In preparing the aqueous emulsion, the lubricant and the emulsifiers are melt-blended and the blend slowly poured into heated water. The resulting emulsion is highly stable and thus maintains a high degree of uniformity over extended periods of use. The concentration, by weight, of the non-aqueous constituents, i.e., solids, may vary from about 5 percent to about 20 percent but is preferably about 8 to about 12 percent since such concentrations will permit application of the desired amount of solids on the yarn in the most effective manner. The emulsion is applied to yarn preferably by using a roller, and about 0.2 percent to 1.0 percent by weight of the solids based on the weight of the resulting yarn is applied.

The lubricating compositions of this invention are adapted for use on yarns of polyamides such as polyhexamethylene adipamide (6-6 nylon), polycaproamide (6 nylon) or other well-known nylons. For purposes of the present invention, the yarns are made in accordance with present commercial practices and in the usual range of deniers for textile applications.

Because of the high density of the yarn in the chamber and the high temperature to which the chamber is heated, the role of the yarn lubricating composition is especially critical. The composition must lubricate the yarn sothat it moves smoothly and uniformly as it is being compacted and forced through the heating chamber. Heat must be transmitted from the walls of the chamber to the center of the compacted yarn core in a uniform manner so that bulk potential and dyeing uniformity will not be impaired. Also, the compositions must be stable to the high temperatures of the heated crimping chamber and not cause obnoxious fumes or yarn-damaging thermal decomposition products. Further, the compositions should not be susceptible to temperature-induced interactions in the heated chamber that result in unacceptable losses of yarn strengh. The lubricated nylon yarns prepared in accordance with this invention are particularly suited for bulking by being crimped in a heated stuffing chamber.

As is known, yarns that are bulked by being crimped in a heated stufiing chamber have the ability to develop additional bulk when the yarns are subsequently heated. It will be apparent that yarns which develop the greatest bulk in fabric forms are the mose desirable for the production of high-bulk fabrics with a textured appearance.

In measuring the "bulk potential of yarns prepared with compositions of this invention a contraction-under-load test is used. When a knitted fabric is prepared from a yarn having latent bulk that is to be released by heat, the bulking force will be the force in excess above that needed to overcome the restraining force of the knitted stitch. The value of 0.001 gram per denier is taken as an average of the knitted stitch restraining force. A suitable length of yarn is measured off and loaded with an appropriate weight so as to provide the required restraint, The yarn is then heated at conventional heat treating temperatures and the loss in length determined. The loss in length is related to the bulk developed. For evaluation purposes, the length at maximum bulk is compared to a standard length, which conveniently is the length at minimum bulk. The length at minimum bulk is determined by applying a load of sufficient force to straighten the crimp but which will not cause yarn elongation; i.e., a length attributable only to crimp removal. A common embodiment of this test consists of producing a skein by winding revolutions of a 70-denier yarn onto a reel having a circumference of 1 meter. A weight of 14 grams is aflixed to the skein, and the skein is hung from a peg or rod in an oven heated to a temperature of 121 C. The skein is heated for 5 minutes after which it is allowed to cool for at least 15 minutes and the length, with the l4-gram weight, is determined. This value is recorded as the maxi mum-bulk length. An additional weight of 1346 grams is afiixed to the yarn and the length again measured. This length is recorded as the minimum-bulk length. The percent bulk is then calculated from the formula minimum-bulk length maximum-bulk length minimum-bulk length This test is used in the example which follows and the percent bulk values given are the average of five determinations. In the example, all parts are by weight.

EXAMPLE A freshly-spun, 6--6 nylon yarn having 34 filaments is treated with a 10% emulsion of a composition of this invention. The emulsion is prepared by mixing together 58 parts of refined coconut oil, 27 parts of the tetraoleate-laurate pentaester of the condensate obtained by condensing one molecular proportion of sorbitol with 30 molecular proportions of ethylene Oxide, and 15 parts of the polyether obtained by condensing one molecular proportion of nonylphenol with 6 molecular proportions of ethylene oxide, melt-blending the mixture at 60 C., and pouring the blend, with agitation, into water. Ten parts of the melt-blended mixture are poured into 90 parts of water heated to a temperature of 60 C. The resulting 10% emulsion is highly stable and shows no evidence of creaming. Typically, the lubricant has an initial smoke point of about 170 C. and a viscosity of 190 cps. at 25 C. The treated yarn, containing 0.54% of the emulsion solids, is then cold drawn to produce a high quality 70-denier yarn suitable for crimping in a stufiing chamber. The yarn is then crimped using a Foster Type B crimper. The crimper is equipped with a crimping chamber 9.5 inches (24.1 centimeters) in length and it is heated at a temperature of 210 C. The yarn is crimped in a very uniform manner without the production of fumes or deposits and has a 37% bulk value. This yarn is converted to a knitted fabric having a high, uniform bulk. The fabric is very uniform with no evidence of streaks, and there is no significant loss in yarn strength.

In the example, the lubricant was applied as a spinfinish. Generally the resulting yarn will be packaged and shipped to a fabric producer who crimps the yarn and then manufactures fabrics. The stability of the lubricant and absence of gel residues therefrom are addditional con- Percent bulk- X100 siderations that make the yarn product of this invention of particular commercial interest.

While the invention has been described in detail, it will be appreciated that changes can be made from the specific details without departing from its scope.

What is claimed is:

1. Continuous filament nylon yarn having on its surface a lubricating composition consisting essentially, by weight, of about to parts of coconut oil, about 25 to 30 parts of the tetraoleate-laurate pentaester of the condensate of one mol of sorbitol and about 30 mols of ethylene oxide, and about 15 parts of the polyether condensate of one mol of nonylphenol and about 6 mols of ethylene oxide.

2. Continuous filament nylon yarn according to claim 1 in which the lubricating composition is present in an amount of about 0.2 to 1.0 weight percent, based on the weight of the resulting yarn.

3. Bulkable continuous filament nylon yarn having on its surface a lubricating composition consisting essentially, by weight, of about 58 parts of coconut oil, about 27 parts of the tetraoleate-laurate pentaester of the condensate and one mol of sorbitol and about 30 mols of ethylene oxide, and about 15 parts of the polyether condensate of one mol of nonylphenol and about 6 mols of ethylene oxide.

4. Yarn according to claim 3 in which the lubricating composition is present in an amount of about 0.2 to 1.0 weight percent, based on the weight of the resulting yarn.

References Cited UNITED STATES PATENTS 2,436,979 3/1948 Standley et a1. 117-l39.5 2,964,470 12/1960 Wentworth 117-139.5 3,248,258 4/1966 Coats 1l7138.8 3,277,000 10/1966 Chandler 117-1395 WILLIAM D. MARTIN, Primary Examiner. T. G. DAVIS, Assistant Examiner.

. U.S. Cl. X.R. 

